Is there a DIY for replacing an alternator?

[Shinare]

I have a 2007 LB (as seen in my signature) and this morning I woke up to a battery that would not crank the engine. I knew it was coming but I was fooling myself into thinking it was going to "just get better". The last couple days I have been noticing a little less enthusiasm in my starter cranking over the engine. This morning it turned the engine a little and then a bunch of hurried clicks. I'm going to swing the batter by an autozone to test, but if its not the battery then I guess its the alternator. and was wondering if there was a DIY. I did a search and nothing came up, but I did find the service manual for it.